// EXOBND.cpp
// This module extracts nodes from various object types (bricks, shells, beams, SPH elements)
// Originally developed by MDU for Optris integration (10/00)

#include <vector>
#include <algorithm>
#include <memory>

// Define real type based on precision needs
using Real = double;

// Object type constants
namespace Object {
    constexpr int BRICK = 1;
    constexpr int SHELL = 2;
    constexpr int BEAM = 3;
    constexpr int SPH = 4;
}

// Extraction type flags
namespace Extraction {
    constexpr int INIT = 0x01;       // Initialization phase
    constexpr int ALL = 0x02;        // Extract all nodes
    constexpr int ELEMENT = 0x04;    // Extract element nodes
    constexpr int EXPLICIT = 0x08;   // Extract explicit nodes
    constexpr int ADA = 0x10;        // Adaptive extraction
}

/**
 * @brief Extracts nodes from various object types
 * 
 * This function processes different object types to extract nodes:
 * 1) Bricks (8-node elements)
 * 2) Shells (4-node elements)
 * 3) Beams (2-node elements)
 * 4) SPH elements (1-node)
 * 
 * @param objectData Object data structure
 * @param brickElements Brick element data
 * @param brickCodes Brick codes
 * @param shellElements Shell element data
 * @param shellCodes Shell codes
 * @param beamElements Beam element data
 * @param beamCodes Beam codes
 * @param sphElements SPH element data
 * @param sphCodes SPH codes
 * @param extractedNodes Output: List of extracted nodes
 * @param nodeFlags Node flags array
 * @param boundaryNodes Boundary nodes array
 * @param nodePointers Node pointer indices
 * @param cot12 COT12 data
 * @param cot23 COT23 data
 * @param cot34 COT34 data
 * @param cot41 COT41 data
 * @param midCot MIDCOT data
 * @param fiNum FINUM data
 * @param extractionType Type of extraction to perform
 */
void ExtractObjectNodes(
    const ObjectData& objectData,
    const std::vector<int>& brickElements,
    const std::vector<int>& brickCodes,
    const std::vector<std::array<int, 6>>& shellElements,
    const std::vector<int>& shellCodes,
    const std::vector<std::vector<int>>& beamElements,
    const std::vector<int>& beamCodes,
    const std::vector<int>& sphElements,
    const std::vector<int>& sphCodes,
    std::vector<int>& extractedNodes,
    std::vector<int>& nodeFlags,
    const std::vector<int>& boundaryNodes,
    const std::vector<std::array<int, 6>>& nodePointers,
    const std::vector<int>& cot12,
    const std::vector<int>& cot23,
    const std::vector<int>& cot34,
    const std::vector<int>& cot41,
    const std::vector<int>& midCot,
    const std::vector<int>& fiNum,
    int extractionType)
{
    // Initialize counters
    int totalNodesExtracted = 0;
    std::vector<int> tempNodeBuffer; // Temporary storage for extracted nodes

    // Initialize node pointers
    nodePointers[Extraction::INIT][0] = 1;
    nodePointers[Extraction::ADA][0] = 1;

    // Process each object
    for (int objIdx = 0; objIdx < objectData.numObjects; ++objIdx) {
        int nodesFromElements = 0;
        int nodesFromFaces = 0;
        int nodesExplicit = 0;

        // Get object properties
        int objPtr = objectData.objectPointers[objIdx];
        int extractAllFlag = objectData.properties[objPtr + 1] & extractionType;
        int extractElementFlag = objectData.properties[objPtr + 2] & extractionType;
        int extractExplicitFlag = objectData.properties[objPtr + 19] & extractionType;

        // Determine if extraction should be performed for this object
        bool shouldExtract = false;
        if (extractionType == Extraction::INIT) {
            shouldExtract = true;
            extractAllFlag = extractionType;
        } else if (extractElementFlag == extractionType || extractAllFlag == extractionType) {
            shouldExtract = true;
        }

        // Additional check for adaptive extraction
        if (shouldExtract && extractionType == Extraction::ADA) {
            int adaptiveFlag = objectData.properties[objPtr + 24] & Extraction::ADA;
            if (adaptiveFlag != Extraction::ADA) {
                shouldExtract = false;
            }
        } else {
            // Reset counters if not extracting
            objectData.properties[objPtr + 6] = 0;
            objectData.properties[objPtr + 7] = 0;
        }

        if (shouldExtract) {
            // ----------------------------------------------------------
            // Process nodes to exclude (DELNOD)
            // ----------------------------------------------------------
            int delStart = nodePointers[objIdx][1];
            int delEnd = nodePointers[objIdx + 1][1] - 1;
            
            for (int j = delStart; j <= delEnd; ++j) {
                int nodeId = boundaryNodes[j];
                nodeFlags[nodeId] = objIdx;
            }

            // ----------------------------------------------------------
            // Extract nodes from BRICK elements (8-node)
            // ----------------------------------------------------------
            int brickStart = nodePointers[objIdx][2];
            int brickEnd = nodePointers[objIdx + 1][2] - 1;
            
            if (brickEnd >= brickStart) {
                ExtractNodesFromBricks(
                    brickElements, brickCodes, 
                    nodeFlags, extractedNodes, tempNodeBuffer,
                    totalNodesExtracted, nodesFromElements, nodesFromFaces,
                    objIdx, extractAllFlag, extractionType,
                    brickStart, brickEnd);
            }

            // ----------------------------------------------------------
            // Extract nodes from SHELL elements (4-node)
            // ----------------------------------------------------------
            int shellStart = nodePointers[objIdx][3];
            int shellEnd = nodePointers[objIdx + 1][3] - 1;
            
            if (shellEnd >= shellStart) {
                ExtractNodesFromShells(
                    shellElements, shellCodes, 
                    nodeFlags, extractedNodes, tempNodeBuffer,
                    cot12, cot23, cot34, cot41, midCot, fiNum,
                    totalNodesExtracted, nodesFromElements, nodesFromFaces,
                    objIdx, extractAllFlag, extractionType,
                    shellStart, shellEnd);
            }

            // ----------------------------------------------------------
            // Extract nodes from BEAM elements (2-node)
            // ----------------------------------------------------------
            int beamStart = nodePointers[objIdx][4];
            int beamEnd = nodePointers[objIdx + 1][4] - 1;
            
            if (beamEnd >= beamStart) {
                ExtractNodesFromBeams(
                    beamElements, beamCodes, 
                    nodeFlags, extractedNodes, tempNodeBuffer,
                    totalNodesExtracted, nodesFromElements, nodesFromFaces,
                    objIdx, extractAllFlag, extractionType,
                    beamStart, beamEnd);
            }

            // ----------------------------------------------------------
            // Extract nodes from SPH elements (1-node)
            // ----------------------------------------------------------
            int sphStart = nodePointers[objIdx][5];
            int sphEnd = nodePointers[objIdx + 1][5] - 1;
            
            if (sphEnd >= sphStart) {
                ExtractNodesFromSph(
                    sphElements, sphCodes, 
                    nodeFlags, extractedNodes, tempNodeBuffer,
                    totalNodesExtracted, nodesFromElements, nodesFromFaces,
                    objIdx, extractAllFlag, extractionType,
                    sphStart, sphEnd);
            }

            // ----------------------------------------------------------
            // Process explicit nodes
            // ----------------------------------------------------------
            if (extractionType != Extraction::ELEMENT) {
                int explicitStart = nodePointers[objIdx][0];
                int explicitEnd = nodePointers[objIdx + 1][0] - 1;
                
                for (int j = explicitStart; j <= explicitEnd; ++j) {
                    int nodeId = objectData.explicitNodes[j];
                    if (nodeFlags[nodeId] != objIdx) {
                        nodesExplicit++;
                        tempNodeBuffer[nodesFromFaces + nodesExplicit] = nodeId;
                        nodeFlags[nodeId] = objIdx;
                    }
                }
            }

            // Update object node counts
            objectData.properties[objPtr + 6] = nodesFromElements;
            objectData.properties[objPtr + 7] = nodesFromElements + nodesFromFaces + nodesExplicit;

            // Add face nodes and explicit nodes to main extracted nodes list
            for (int j = 0; j < nodesFromFaces + nodesExplicit; ++j) {
                extractedNodes[totalNodesExtracted + j] = tempNodeBuffer[j];
            }

            totalNodesExtracted += nodesFromFaces + nodesExplicit;
        }

        // Update extraction pointers for this object
        nodePointers[Extraction::INIT][objIdx + 1] = nodePointers[Extraction::INIT][objIdx] 
                                                    + nodesFromElements + nodesFromFaces + nodesExplicit;
        
        nodePointers[Extraction::ELEMENT][objIdx] = nodesFromElements;
        nodePointers[Extraction::ALL][objIdx] = nodesFromFaces;
        nodePointers[Extraction::EXPLICIT][objIdx] = nodesExplicit;

        // Initialize adaptive extraction pointers
        nodePointers[Extraction::ADA][objIdx + 1] = nodePointers[Extraction::ADA][objIdx];
        nodePointers[Extraction::ADA + 1][objIdx] = 0;
        nodePointers[Extraction::ADA + 2][objIdx] = 0;
        nodePointers[Extraction::ADA + 3][objIdx] = 0;
    }
}

// Helper functions for specific element types
void ExtractNodesFromBricks(
    const std::vector<int>& elements,
    const std::vector<int>& codes,
    std::vector<int>& nodeFlags,
    std::vector<int>& extractedNodes,
    std::vector<int>& tempBuffer,
    int& totalCount,
    int& elementCount,
    int& faceCount,
    int objectId,
    int extractAllFlag,
    int extractionType,
    int startIdx,
    int endIdx)
{
    // Implementation for 8-node brick elements
    // Would include logic to extract nodes based on codes and flags
}

void ExtractNodesFromShells(
    const std::vector<std::array<int, 6>>& elements,
    const std::vector<int>& codes,
    std::vector<int>& nodeFlags,
    std::vector<int>& extractedNodes,
    std::vector<int>& tempBuffer,
    const std::vector<int>& cot12,
    const std::vector<int>& cot23,
    const std::vector<int>& cot34,
    const std::vector<int>& cot41,
    const std::vector<int>& midCot,
    const std::vector<int>& fiNum,
    int& totalCount,
    int& elementCount,
    int& faceCount,
    int objectId,
    int extractAllFlag,
    int extractionType,
    int startIdx,
    int endIdx)
{
    // Implementation for 4-node shell elements
    // Would include logic to extract nodes based on codes and flags
}

// Similar helper functions for beams and SPH elements would follow...